1. Field of the Invention
The invention relates in general to a film scanning technology, and more particularly to a film scanning method capable of scanning and recognizing a film to obtain a clear film scan image through a single scanning.
2. Description of the Related Art
The film scanner is currently directed towards the integration of many film scanning functions, such as reading the positive film (the reversal film or the slide film) as well as the negative film (the black/white film and the color film). High accuracy in color recovery is expected on the film scanner. Since the film itself carries a base background color, manual color correction is needed during scanning. Films from different manufacturers usually have different base background colors and negatives have large tolerance in exposure (for example negatives have tolerance in twice exposure). Therefore, during negative scanning, scanning calibration cannot be performed through the use of standard color sheet which is applicable in the scanning of an ordinary photo. Before scanning a film by the prior scanning device, manual adjustment on the film is needed. Examples of manual adjustment include color calibration (change in the hue of color), exposure calibration (brightness level) and color saturation processing on pre-scanned pictures. Thus, this kind of the film scanner needs to repeatedly scan the film for many times, and complete film adjustment and calibration function manually. However, there is difference in accuracy between manual color calibration result and the optimum color of the film itself. Meanwhile, aberration even exists in the films of the same model from the same manufacturer. Therefore, accurate recovery of film scanning cannot be implemented just through the recognition of the manufacturers and the film type.